Functions and features: 1 Offer 4 / 8 RJ11 output ports to connect 4 / 8 sensors or display systems. 2 Offer 2 online RJ12 ports for 2 or more 4/ 8-port alarm unit using at same time to be 12/16/20/24/28/32-port central control alarm system. 3 Offer 1 external remote RJ12 port to connect various external alarm signal / siren such as ES521IR to realize long-distance remote function. 4 Metal case, LED indication function to show work condition of every defense area. 5 Can customize wifi Bluetooth reception function. 6 Built-in rechargeable lithium battery with 7 days standby time in maximum, low battery indication function. 7 Alarm will be triggered when alarm unit is detached. 8 Code modification function. 9 Offer power switch. 10 Built-in short-circuit protection function. Main parameters: 1Size: 165 X 74 X 33mm. 2Case: ABS. 3Output port: 4 / 8 ports of RJ11. 4Alarm volume: â?¥100DB. 5Standby time of built-in rechargeable lithium battery: 7 days. 6Code modification function: yes. 7Low battery indication: yes. 8External power on / off indication: yes. 9Power input port: DC. Optional accessories: 1 Power adapter: 5V/8A. 2 AS3X series IR remote keys. 3 ES521IR external remote signal. 4 RJ-2 cable. For more functions and accessories, kindly please contact our sales or local distributor.